Propulsion output is limited to ensure safety of battery warning and small claims court case

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I flew my Phantom 3 Professional on Maui in April 2016 shortly after updating the software to V1.8.80. Prior to this, I completed over 100 flights without any issues. About 12 minutes into the flight, a “propulsion output is limited to ensure the safety of the battery” warning popped up on the DJIGo app. I had never seen this error before the software update. I had no idea what this meant or what to do about it, so tried to troubleshoot and then tried to bring my Phantom home. However, its maximum speed seemed to be reduced by about half even when I was trying to fly forward at full speed. A few minutes later, when the Phantom was about half a mile away (it would have been home at that point if the max speed was not reduced), the battery ran down so far that it auto landed. I tried to recover it but was unable to find it.

The battery had less than 25 cycles and was still under warranty, as was the Phantom. I analyzed the flight record and discovered that after the warning appeared, my max speed was limited by about 40% when the elevator input was at max forward, even though my battery drain rate was unchanged.

This cut my range in half during the last 2-3 minutes of flight, very likely resulting in the loss. I contacted DJI tech support for a warranty replacement and uploaded the flight record as requested. A few months of back-and-forth communication followed, during which DJI attributed the loss to the wind, unforeseen environmental factors, and pilot error. DJI never explained what I had been doing differently from previous flights that caused the “propulsion limited…” warning and stated that the warning in no way indicated a problem with the performance of the Phantom. Ultimately, I filed a small claims suit for the cost of the Phantom and accessories (OEM impellers and battery) that I lost. In court, DJI argued that pilot error caused the loss and that a loss was not covered by warranty because there was no way for DJI to examine the Phantom. However, DJI was unable to explain what pilot actions caused the propulsion to be limited. I argued that I lost my Phantom because it’s range was cut in half in the last 2-3 minutes of flight and that DJI never informed Phantom owners about what could cause this or how to prevent it. I also pointed out that complete loss of the Phantom due to hardware failure was covered by warranty. The court ruled in my favor and awarded me the cost of the Phantom, accessories, and court fees.

Needless to say, I’m very disappointed that I had to take the time and effort (six months and over 20 hours of my time) to go to court to get warranty service for my Phantom. I can’t imagine buying another DJI product until there’s a drastic change in DJI customer service policies. I should mention that I did ask for DJI feedback on this before posting, and the feedback was, “we are working on improving both the statement of the warning and our customer service, based on your and other customer’s feedbacks. We are in the process of revising that particular warning involved in this case, for more clear instructions and better wording.”
 

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Over 10km flight at close to an average speed of 40km/hr.... Thats good performance for the AC and battery. And it seemingly autolanded beautifully to protect itself from falling out of the sky (its the over water part that killed the chance of a happy ending).

Based on your evidence if your speed wasn't limited you could have travelled 850m closer to home before the autoland, you needed 900m so you could have walked out to meet the AC for a nice hand catch.

That would have still been pushing the limits of the AC and battery.

I'm guessing this matter was settled on the papers or DJI didn't fight real hard. Thas not uncommon, the cost of defending the matter would have far exceeded the damages awarded.

In any case it's a nice outcome given some of the stories I have seen here where people have been fobbed off and ended up with a total loss. Perhaps if you posted the flight log it may help some people who face similar issues in future.
 
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Actually, a rep from DJI traveled two hours to attend the court hearing. Immediately prior to the trial, DI offered me 50% off a new Phantom 3, which I turned down. The hearing lasted aout 20 minutes. Here is the flight record.
 

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Meta4

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I argued that I lost my Phantom because it’s range was cut in half in the last 2-3 minutes of flight and that DJI never informed Phantom owners about what could cause this or how to prevent it. I also pointed out that complete loss of the Phantom due to hardware failure was covered by warranty. The court ruled in my favor and awarded me the cost of the Phantom, accessories, and court fees.

Needless to say, I’m very disappointed that I had to take the time and effort (six months and over 20 hours of my time) to go to court to get warranty service for my Phantom. I can’t imagine buying another DJI product until there’s a drastic change in DJI customer service policies.
Looking at the flight data, I'd say that you are very lucky to have had a sympathetic court that didn't understand Phantom flying and that DJI didn't push a little harder.
The flight shows poor decisions and planning that would have put your Phantom at risk regardless of the propulsion output limited issue.
You didn't begin to return home until you were at 23% battery and over 6000 feet out and up 400 feet on a day with significant wind.
23% on the battery gauge is very different from 23% on your car's fuel gauge.
You started the flight with a battery voltage of 16.9V but at 23% you are down to 14.1V and the battery cannot give what it could at the start of the flight and furthermore, what it can give is falling fast at that level.
If you are flying far from home, a safety margin is a valuable thing.
You should aim to be home by 30% or 20% at most.
But after 30% and one warning, that should have been your wake up call but you turned west and kept flying rather than heading for home.


I suspect that if you hadn't lost the Phantom that time and continued flying like that you would have lost it sooner rather than later.
 
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If the Phantom hadn't limited your speed, it would have taken the voltage down to a point wher the aircraft would have powered off and fallen out of the sky because the battery was too low on voltage to power the aircraft.pretty sure this is a designed failsafe to keep it in the air and enable one to safely land the aircraft. It does this by by lessening voltage usage (volts don't always = battery %). Super happy for you that you won though.
 
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I see some call this pilot error and on a situation other than this one I would also. But this in my opinion is more about pushing updates without any info on what they consist of, or what to expect since being added.

DJI has plenty of methods to notify us on what is going on.
 
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I see some call this pilot error and on a situation other than this one I would also. But this in my opinion is more about pushing updates without any info on what they consist of, or what to expect since being added.

DJI has plenty of methods to notify us on what is going on.
I'm partially with Frank here. While the pilot's "actions" were at fault (pilot is ultimately responsible for what happens with the aircraft) DJI needs to really step up their game in notifications, wording, and FW descriptions. There is a lot of room for improvement and most of what we do know comes from Trial & error and user input on this forum.
 
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Battery output limited often happens when the battery is not fully locked into the chamber. Has happened to me that way. Fortunately the battery never slipped out completely.
 
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Battery output limited often happens when the battery is not fully locked into the chamber. Has happened to me that way. Fortunately the battery never slipped out completely.
False. It happens when the flight controller senses that the motors are currently requiring more power than the battery will be able to maintain at its current level.
 
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False. It happens when the flight controller senses that the motors are currently requiring more power than the battery will be able to maintain at its current level.
Sorry Dwight Shroot, Your false is false. I have actually had this happen to me under those circumstances and it also happens if the battery is either too cold or too hot. What you say is correct but various things can cause the reduced output.
 
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Sorry Dwight Shroot, Your false is false. I have actually had this happen to me under those circumstances and it also happens if the battery is either too cold or too hot. What you say is correct but various things can cause the reduced output.
I 100% agree. A battery that is partially making contact WILL indeed give erroneous readings and trigger this limited propulsion message. I can tell you first hand this is fact. I've seen it on two different aircraft (1 was P3P and the other was P3A.... one is still flying the other sadly is MIA) and both we from the same problem.
 

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